Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 63
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Dairy Sci ; 97(3): 1202-9, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24440258

RESUMEN

Parmigiano Reggiano cheese dairies develop specific cheese-making strategies to adapt the variable characteristics of raw, not standardized milk to the final goal of obtaining cheese consistent with the standard. Analyzing 1,175 cheese-making reports from 30 out of 383 dairies associated with the Parmigiano Reggiano Consortium in 2010 and 2011, 4 groups of Parmigiano Reggiano dairies using specific cheese-making technologies were discriminated by means of multiple linear discriminant analysis. Cheese makers manage cheese-making practices to obtain curd with different roughness properties, classified according to jargon words such as "rigata" and "giusta" or synonyms, because they believe that the roughness of the cheese curd surface immediately after the extraction from the vat is associated with different whey-draining properties and to the final outcome of the cheese. The aspect of the surfaces of the curds produced by the 4 groups of dairies was different according to the technology applied by each group. Cutting of the coagulum when it is still soft for a longer time and faster cooking of the cheese curd grains were associated with a less rough appearance of the surface of the curd, whereas under the opposite conditions, cutting the coagulum when it is firm for a shorter time, led to a curd with a rougher surface. These findings partially support the traditional feeling of Parmigiano Reggiano cheese makers, who consider the curd surface aspect one of the main drivers for their technological choices; to date, however, no data are provided about correlation between the aspect of the curd and the quality of the ripened cheese. If a sufficiently strong correlation could be demonstrated by the future development of the research, the operational effectiveness of Parmigiano Reggiano dairies will be able to largely benefit from the availability of sound and early process markers.


Asunto(s)
Queso/análisis , Manipulación de Alimentos/métodos , Tecnología de Alimentos/métodos , Leche/química , Animales , Bovinos , Industria Lechera
2.
J Endocrinol Invest ; 36(6): 390-5, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23095310

RESUMEN

Androgens' metabolism and activity are gaining a more and more important role in human physiology particularly referring to aging and to neurodegenerative diseases. Androgen treatment is often required for long-lasting disorders. In order to improve their duration and effects, androgens can be administered as esters of carboxylic acids. The novelty of our research is the use of esters of androgens with specific unsaturated fatty acids, in order to reduce possible side effects particularly related to chronic pathologies with altered lipid homeostasis such as X-linked adrenoleukodystrophy and cardiovascular disorders. Thus the esters of the main androgenic substances testosterone, dihydrotestosterone (DHT) and their metabolite 5α-androstan-3α,17ß-diol were chemically obtained by coupling with different unsaturated fatty acids. To this aim, fatty acids with various degree of unsaturation and belonging to different series were selected. Specifically, oleic acid (18:1, n-9), linoleic acid (18:2, n-6), and the n-3 fatty acids, α-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6) were used obtaining corresponding esters with acceptable yields and good degree of purity. All the synthesized compounds were tested for their cytotoxic activities in mouse NIH3T3 and human astrocyte cell lines. The esters demonstrated good tolerability and no in vitro cytotoxic effect in both cell cultures. After these promising preliminary results, the esters will be suitable for in vivo studies in order to ascertain their pharmacokinetic characteristics and their biological effects.


Asunto(s)
Ésteres/síntesis química , Ácidos Grasos Insaturados/química , Congéneres de la Testosterona/síntesis química , Congéneres de la Testosterona/uso terapéutico , Adipocitos/efectos de los fármacos , Adipocitos/fisiología , Animales , Astrocitos/efectos de los fármacos , Astrocitos/fisiología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Ésteres/farmacología , Ésteres/uso terapéutico , Terapia de Reemplazo de Hormonas/métodos , Humanos , Ratones , Modelos Biológicos , Células 3T3 NIH , Congéneres de la Testosterona/farmacología
3.
PLoS One ; 14(9): e0221960, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31498841

RESUMEN

In Argentina, NDM metallo-ß-lactamase was first reported in 2013. By now, it has disseminated throughout the country in diverse Gram negative bacteria. Here, we report the case of a paediatric patient that underwent a 1-year hospitalisation due to erythrodermic psoriasis in 2014 and received multiple antimicrobial treatments. During his stay, five isolates were obtained from rectal swabs (rs) or blood culture (bc) suspicious of carbapenemase production: a K. quasipneumoniae subsp. quasipneumoniae (rs), Citrobacter freundii (rs), Escherichia coli (bc), Enterobacter cloacae (rs), and a Serratia marcescens (bc). The isolates were studied with broth microdilution, biparental conjugation and plasmid and whole genome sequencing (Illumina). All isolates harboured an 138,998-bp type 1 IncC plasmid that carried blaNDM-1, bleMBL, blaCMY-6, rmtC, aac(6')-Ib, and sul1 resistance genes. Additionally, the blaNDM-plasmids contained ISKpn8 an insertion sequence previously described as associated only to blaKPC. One isolate, a colistin-resistant E. coli, also carried a mcr-1-containing an IncI2 plasmid, which did not harbour additional resistance. The whole genome of K. quasipneumoniae subsp. quasipneumoniae isolate was fully sequenced. This isolate harboured, additionally to blaNDM, three plasmid-mediated quinolone resistance genes: qnrB4, qnrB52 and aac(6')-Ib-cr1. The E. cloacae isolate also harboured qnrA1. These findings alert to the underestimated horizontal dissemination of multidrug-resistant plasmids limiting treatment options with last resort antimicrobials.


Asunto(s)
Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Plásmidos/genética , Antibacterianos/farmacología , Niño , Preescolar , Farmacorresistencia Bacteriana/genética , Enterobacteriaceae/clasificación , Enterobacteriaceae/efectos de los fármacos , Escherichia coli/genética , Transferencia de Gen Horizontal , Hospitales , Humanos , Filogenia , Psoriasis/microbiología
5.
J Inherit Metab Dis ; 30(5): 828, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17602313

RESUMEN

X-linked adrenoleukodystrophy (X-ALD) is an inherited neurodegenerative disorder associated with reduced very long-chain fatty acid beta-oxidation, mainly affecting the nervous system, the adrenal cortex and the testes. The clinical manifestations of hypogonadism, alopecia and the impairment of the enzyme 5alpha-reductase, which converts testosterone into dihydrotestosterone, clearly point to an involvement of androgens in this pathology. The disease is characterized by mutations in the ABCD1 gene, which codes for the peroxisomal ABC half-transporter ALDP, and by a broad range of clinical manifestations. The altered function of ALDP can be compensated by the overexpression of proteins belonging to the same family of ABC half-transporters. A promising therapeutic approach is represented by the activation of these proteins by specific agonists. In this study we evaluated the effect of the testosterone metabolite dihydrotestosterone (DHT) and 5alpha-androstan-3alpha,17beta-diol (3alpha-diol) on the expression of the ABC half-transporters encoded by the ABCD2 and ABCD3 genes, in fibroblasts drawn from controls and from two affected brothers. The two patients presented the same mutation in exon 9 but had different clinical manifestations, one patient being asymptomatic and the second one severely affected. When the cells were stimulated with testosterone metabolites, only the severely affected patient showed a significant increase in ABCD2 mRNA levels, while the ABCD3 expression remained unchanged in both patients.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Adrenoleucodistrofia/genética , Andrógenos/farmacología , Androstano-3,17-diol/farmacología , Dihidrotestosterona/farmacología , Fibroblastos/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Mutación , Subfamilia D de Transportadores de Casetes de Unión al ATP , Miembro 1 de la Subfamilia D de Transportador de Casetes de Unión al ATP , Transportadoras de Casetes de Unión a ATP/biosíntesis , Transportadoras de Casetes de Unión a ATP/metabolismo , Adrenoleucodistrofia/metabolismo , Andrógenos/metabolismo , Androstano-3,17-diol/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Dihidrotestosterona/metabolismo , Exones , Fibroblastos/metabolismo , Humanos , Masculino , ARN Mensajero/metabolismo , Índice de Severidad de la Enfermedad , Testosterona/metabolismo
6.
Infect Genet Evol ; 54: 374-378, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28739428

RESUMEN

All VIM-producing Enterobacteriaceae (six Enterobacter cloacae) submitted to the Argentinian Reference Laboratory in Antimicrobial Resistance in the period 2008-13 were characterized. The isolates were referred from 6 nosocomial institutions located in 5 different cities across the country. All isolates showed carbapenem disk diffusion inhibition zones ≤22mm and synergism between a carbapenem disk and EDTA/SMA. The six isolates were PCR positive for blaVIM. Imipenem MICs were ≤1 to 8µg/ml. Typing by PFGE and MLST distinguished six pulsotypes and sequence types with blaVIM located on novel class 1 integron arrays: ECL-1: ST182, In883; ECL-2, ST90, In885; ECL-3, ST88, In346 with blaVIM-11; ECL-4, ST184, In900; ECL-5, ST749-new, In900; ECL-6, ST91 and uncharacterized In. Only ECL-2 was able to transfer blaVIM-2 to E. coli J53 by biparental conjugation. blaVIM was located in plasmids of 53-82Kb and in the chromosome (ECL-1 and ECL-5). The diversity of clones, class 1 integrons, plasmids and location of blaVIM, reveals the plasticity of the genetic elements described and highlights the importance of surveillance programs as tools to identify the transmission of these highly resistant metallo-ß-lactamase-producing Enterobacteriaceae.


Asunto(s)
Enterobacter cloacae/clasificación , Infecciones por Enterobacteriaceae/microbiología , Integrones , beta-Lactamasas/genética , Anciano de 80 o más Años , Antibacterianos/química , Proteínas Bacterianas/genética , Carbapenémicos/química , Infección Hospitalaria/microbiología , ADN Bacteriano/genética , Enterobacter cloacae/genética , Enterobacter cloacae/aislamiento & purificación , Femenino , Humanos , Imipenem/farmacología , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Tipificación de Secuencias Multilocus
7.
Infect Genet Evol ; 44: 145-146, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27287559

RESUMEN

The worldwide dissemination of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae ST258 demands a rapid PCR-based typing method to detect unique genes of the ST258 clone. This study evaluates a PCR developed by Adler et al. (2014) for the detection of ST258 in K. pneumoniae clinical isolates centered on the identification of the pilv-I and prp genes. We tested 143 clinical isolates from Argentina (n=109), Chile (n=1), Colombia (n=1), Costa Rica (n=2), Ecuador (n=5), El Salvador (n=2), Nicaragua (n=5), Panamá (n=2), Paraguay (n=2), Perú (n=3) and Trinidad and Tobago (n=11) recovered from 2006 to 2015. blaKPC, pilv-l and prp genes were detected by PCR and sequenced by standard procedures. ST258 and non-ST258 were defined by PFGE and/or MLST. Isolates were grouped according to PFGE patterns: 58 were compatible with ST258 (group 1) and 85 with non-ST258 (group 2). MLST study was done on an arbitrary selection of isolates. The pilv-l gene was present only in ST258 isolates, regardless of the presence of the blaKPC gene. Results for the prp gene were variable. Its presence did not define ST258. The pilv-I PCR had a sensitivity and specificity of 100%, respectively, for the detection of ST258 in the isolates under investigation. Given our findings, the pilv-I PCR could replace more time and resource consuming methods, allowing for more rapid detection of the circulating high risk K. pneumoniae clone ST258 in Latin American (LA) countries.


Asunto(s)
Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/genética , Reacción en Cadena de la Polimerasa/métodos , Proteínas Bacterianas/genética , Humanos , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/aislamiento & purificación , América del Sur/epidemiología , beta-Lactamasas/genética
8.
Atherosclerosis ; 59(2): 101-11, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3964338

RESUMEN

The effects of dietary interventions, based on changes of total fat, saturated fatty acids and cholesterol contents and of the polyunsaturated/saturated (P/S) fatty acid ratio of the diet, were studied in normal male and female subjects, living in North Karelia, Finland, and South Italy. In North Karelia the increase of P/S ratio (from 0.15 to 1.2) of the diet for a 6-week period resulted in reduced thromboxane B2 (TxB2) production by collagen-stimulated platelets only in male subjects, whereas plasma total, LDL and HDL cholesterol were reduced in both sexes. After a 6-week return to the original diet, plasma lipid levels were restored in all subjects. In the South Italy study, changes in platelet TxB2 production were observed only after return to the original diet in male subjects. Total and LDL cholesterol were significantly increased during the dietary intervention and returned toward baseline levels after switch back to the original diet. These data indicate that the increase of the P/S ratio in the diet reduces platelet TxB2 formation only in men.


Asunto(s)
Plaquetas/metabolismo , Grasas de la Dieta/farmacología , Tromboxano B2/sangre , Adulto , Colesterol/sangre , Colágeno/farmacología , Enfermedad Coronaria/prevención & control , Grasas de la Dieta/administración & dosificación , Ácidos Grasos/administración & dosificación , Ácidos Grasos/sangre , Ácidos Grasos Insaturados/administración & dosificación , Ácidos Grasos Insaturados/sangre , Femenino , Finlandia , Humanos , Técnicas In Vitro , Italia , Lípidos/sangre , Lipoproteínas/sangre , Masculino , Persona de Mediana Edad , Factores Sexuales
9.
Neurochem Int ; 40(3): 255-60, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11741009

RESUMEN

Hypoxia-hypoglycemia has played an important role in inducing both phospholipase A2 activation and the expression of the early gene c-fos, in the neuroblastoma cell line SK-N-BE, after it has been differentiated by retinoic acid. Under hypoxic-hypoglycemic conditions, arachidonic acid release has found to be significant after 30 min, whereas c-fos expression has required at least 4 h. This model has been obtained by adding glycolytic inhibitor 2-deoxyglucose to the culture and by placing cells in an atmosphere containing 100% N2 for different time periods. This condition has been compared with two different models: NaCN and nitrogen have been used as hypoxic stimuli, without inhibiting the glycolytic pathway, but the same cell cultures have been used. Cell viability and the fall of cellular ATP levels have been evaluated in all the models, in order to monitor and compare the hypoxic cellular damage. Phospholipase A2 activation has been found to be significant in all conditions, even if to a different extent; but only hypoxia combined with the inhibition of the glycolytic pathway, has induced a significant expression of c-fos. It is very difficult to study hypoxic stimuli in 'in vitro' systems. Our study has compared three different models and the one combining gaseous hypoxia and hypoglycemic conditions seems to be very effective in stimulating early events involved in hypoxic phenomena such as phospholipase activation and the expression of the early gene c-fos.


Asunto(s)
Ácido Araquidónico/metabolismo , Hipoglucemia/complicaciones , Hipoglucemia/metabolismo , Hipoxia/complicaciones , Hipoxia/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Diferenciación Celular/efectos de los fármacos , Activación Enzimática/fisiología , Glucólisis/fisiología , Humanos , Hipoxia/inducido químicamente , Neuroblastoma/metabolismo , Neuroblastoma/patología , Nitrógeno , Fosfolipasas A/metabolismo , Fosfolipasas A2 , Cianuro de Sodio , Factores de Tiempo , Tretinoina/farmacología , Células Tumorales Cultivadas
10.
Artículo en Inglés | MEDLINE | ID: mdl-12324232

RESUMEN

X-Adrenoleukodystrophy (X-ALD) is an inherited pathology characterized by very long-chain fatty acid accumulation in plasma as well as in different tissues. The nervous system, the adrenal cortex and the testis are primarily affected. Steroid metabolism which occurs in the adrenal cortex and in the testis might be severely impaired. We have hypothesized that steroids, in particular the androgens, might have a role in this pathology. We have demonstrated that the testosterone metabolite dihydrotestosterone (DHT) and 5alpha-androstan-3alpha,17beta-diol (3alpha-diol), but not testosterone itself, when incubated in skin fibroblasts obtained from patients affected by X-ALD, significantly reduced the abnormal accumulation of very long-chain fatty acids.


Asunto(s)
Adrenoleucodistrofia/metabolismo , Andrógenos/farmacología , Ácidos Grasos/metabolismo , Androstano-3,17-diol/farmacología , Dihidrotestosterona/farmacología , Fibroblastos , Humanos , Piel/citología , Piel/efectos de los fármacos , Piel/patología , Testosterona/metabolismo , Testosterona/farmacología
11.
Artículo en Inglés | MEDLINE | ID: mdl-9250604

RESUMEN

We have studied the biosynthesis of long chain polyunsaturated fatty acids (LC-PUFA) from their precursors in cultured cells undergoing physiological modifications, or under the influence of lipid-lowering drugs or ethanol. The formation of arachidonic acid (AA, 20:4 n-6) from the percursor linoleic acid (LA, 18:2 n-6) in the neuroblastoma cells SK-N-BE is enhanced at early stages of differentiation, and declines when differentiation is complete, in concomitance with maximal accumulation of AA in cell lipids. In the monocytic cells THP-1, the biosynthesis of LC-PUFA is also enhanced by treatment with the HMGCoA reductase inhibitor simvastatin (S), an effect which is reverted by mevalonate and other intermediates of cholesterol synthesis. Maximal activation of LC-PUFA synthesis by S occurs at concentrations lower than those required for maximal inhibition of cholesterol synthesis. In the hepatoma cells HepG2, ethanol decreases the biosynthesis of LC-PUFA while potentiating the incorporation of acetate into cholesterol. LC-PUFA synthesis appears thus to be modulated in the course of cell differentiation and complex interactions between LC-PUFA and cholesterol synthesis occur, as judged from data obtained through pharmacological manipulations.


Asunto(s)
Ácidos Grasos Insaturados/metabolismo , Ácido Araquidónico/metabolismo , Carcinoma Hepatocelular/metabolismo , Diferenciación Celular , Línea Celular , Colesterol/biosíntesis , Inhibidores Enzimáticos/farmacología , Etanol/farmacología , Ácidos Grasos Insaturados/biosíntesis , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Ácido Linoleico , Ácidos Linoleicos/metabolismo , Neoplasias Hepáticas/metabolismo , Lovastatina/análogos & derivados , Lovastatina/farmacología , Ácido Mevalónico/farmacología , Monocitos/metabolismo , Neuroblastoma/metabolismo , Simvastatina , Células Tumorales Cultivadas
12.
Brain Res ; 415(2): 226-32, 1987 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-3607494

RESUMEN

The effects of hypoxia (respiration of 5% O2 for 30 min) and recovery (respiration of air up to 30 min) on brain levels of carbohydrate metabolites, of free arachidonate (FAA) and of several eicosanoids (E) were studied in the rat. Animals were sacrificed before or after 30 min of hypoxia, and during recovery, by microwave radiation (MW). At the end of the hypoxic period, arterial pO2 was reduced to 28 mm Hg and glycemia was elevated. Brain lactate and glucose levels were also elevated, whereas glycogen was unchanged. Levels of free FAA and of E were practically unchanged. During recovery, arterial pO2 values were raised above prehypoxic levels at 5 min and returned to normal within 30 min. The elevated serum glucose declined at 5 min and values returned to normal at 30. Brain glucose was still elevated at 5 min and returned to normal, together with lactate, at 30 min. Brain FAA did not change during recovery, but levels of prostaglandin F2 alpha (PGF2 alpha), prostaglandin E2 (PGF2) and thromboxane B2 (TxB2) were raised, at 5 min, and those of 6-keto-PGF1 alpha were reduced with respect to pre-hypoxia. At the end of recovery, all E were lower than during hypoxia. The results indicate that changes of brain E occur only during recovery from hypoxia. At 5 min of recovery, at high arterial pO2 values, concentrations of all E were elevated, with the exception of 6-keto-PGF1 alpha which was reduced. At 30 min a marked reduction of E levels was observed, possibly resulting from increased clearance following elevation of cerebral blood flow.


Asunto(s)
Corteza Cerebral/análisis , Ácidos Grasos/análisis , Glucosa/análisis , Glucógeno/análisis , Hipoxia Encefálica/metabolismo , Lactatos/análisis , Animales , Glucemia/análisis , Ácido Láctico , Masculino , Prostaglandinas/análisis , Ratas , Ratas Endogámicas , Tromboxano B2/análisis
13.
Brain Res Dev Brain Res ; 63(1-2): 221-7, 1991 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-1790592

RESUMEN

The aim of our study has been to investigate the metabolism of endogenous arachidonic acid or that of radiolabeled arachidonate in astroglial cells, stimulated with platelet activating factor (PAF) and with the calcium-ionphore A23187. Primary cultures of astroglial cells were obtained from brain cortex of one-day-old rats and were characterized by immunofluorescent staining vs glial fibrillary acidic protein. In labeled cells, diacylglycerol was formed after stimulation with platelet activating factor, whereas mainly the release of labeled arachidonic acid from phospholipids was observed after stimulation with calcium-ionophore. Both PAF and the calcium-ionophore A23187 actively stimulated the formation of the cycloxygenase products PGD2, TXB2 and 6-keto-PGF1 alpha, measured by radio- or enzyme-immunoassay. Differences were observed, instead, in the formation of the lipoxygenase metabolites, the hydroxyeicosateraenoic acids, which were measured by high pressure liquid chromatography (HPLC) with on line radiodetection for the labeled products, and Leukotriene C4, measured by radioimmunoassay. The formation of hydroxyacids by stimulated cells was confirmed by gas chromatography-mass spectrometry (GC-MS). In labeled cells, both agonists induced the formation of 12- and 15-hydroxyeicosatetraenoic acids, whereas stimulation of unlabeled cells with calcium ionophore resulted in formation of 12-hydroxyeicosatetraenoic acid and Leukotriene C4. Our results suggest that in astroglial cells, PAF, a compound which is produced in several tissues including brain, mobilizes a selected arachidonic acid pool, possibly associated with diacylglycerol production, from phospholipids, thus activating the conversion of the released fatty acid via the cyclo and the 12-lipoxygenase pathways.


Asunto(s)
Ácido Araquidónico/metabolismo , Astrocitos/efectos de los fármacos , Calcimicina/farmacología , Lipooxigenasa/metabolismo , Factor de Activación Plaquetaria/farmacología , Prostaglandina-Endoperóxido Sintasas/metabolismo , Animales , Astrocitos/enzimología , Células Cultivadas , Diglicéridos/metabolismo , Ácidos Grasos no Esterificados/metabolismo , Hidrólisis , Fosfolípidos/metabolismo , Ratas
14.
Brain Res Dev Brain Res ; 78(2): 169-74, 1994 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-8026072

RESUMEN

The effects of different concentrations of exogenous platelet-activating factor (PAF) on the formation of arachidonic acid-cyclooxygenase metabolites and on the production of inositol phosphates have been investigated in a primary culture of rat astroglial cells. The cells were used at confluence and the purity was checked by immunostaining of the culture with specific antibodies against glial fibrillary acidic protein. Incubation of the cells with PAF (range 10(-9) to 10(-6) M) resulted in maximal accumulation of total inositol phosphate (620 +/- 60% increment over basal values, P < 0.001) at the concentration of 10(-8) M, after 1 min of stimulation. Smaller inositol phosphate accumulation occurred at higher concentrations of the agonist and at longer stimulation time. After 1 min of stimulation with PAF, the accumulation of the cyclooxygenase metabolites, thromboxane B2 (630 +/- 58 vs 20 +/- 2 pg/mg protein in non-stimulated samples) and 6-keto-prostaglandin F1 alpha (132 +/- 15 vs 55 +/- 7 pg/mg protein in non-stimulated samples) was also maximal at 10(-8) M concentration of the agonist. When the cultures were stimulated with PAF or Ca(2+)-ionophore after preincubation with equimolar concentration of the PAF inhibitor BN 52021, a significant inhibition in the synthesis of both inositol phosphates and cyclooxygenase metabolites occurred only in the PAF-stimulated cells.


Asunto(s)
Astrocitos/metabolismo , Diterpenos , Eicosanoides/metabolismo , Fosfatos de Inositol/metabolismo , Lactonas/farmacología , Factor de Activación Plaquetaria/farmacología , 6-Cetoprostaglandina F1 alfa/metabolismo , Animales , Animales Recién Nacidos , Astrocitos/efectos de los fármacos , Calcimicina/farmacología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Ginkgólidos , Inositol/metabolismo , Cinética , Factor de Activación Plaquetaria/antagonistas & inhibidores , Factor de Activación Plaquetaria/metabolismo , Ratas , Tromboxano B2/metabolismo
15.
Neurosci Lett ; 367(3): 269-72, 2004 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-15337247

RESUMEN

X-linked Adrenoleukodystrophy (X-ALD) is a neurodegenerative disease with an endocrinological component since, in addition to the nervous system, the adrenal cortex and the testis are mainly affected, with corresponding clinical signs. 5Alpha-reductase, a key enzyme in steroid hormone metabolism, catalyzes the conversion of testosterone into the potent androgen dihydrotestosterone and other metabolic steps in steroidogenesis. It is present in two isoforms, 5alpha-reductase isoform 1 and 2, that are encoded by different genes. The isoforms are differently expressed in the tissues, where they have distinct physiological relevance. Our study shows that the expression of isoform 2, evaluated by Real-Time PCR, is significantly altered in fibroblasts from patients affected by X-ALD with respect to controls, whereas isoform 1 is not affected. This is the first demonstration of an alteration of 5alpha-reductase isoform 2 gene expression in X-ALD, that may be related to the steroidogenesis impairment and to the specific organ malfunction.


Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Adrenoleucodistrofia/genética , Fibroblastos/metabolismo , Expresión Génica/fisiología , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Adolescente , Adulto , Análisis de Varianza , Niño , Humanos , Masculino , Persona de Mediana Edad , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Mensajero/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos
16.
Neurosci Lett ; 289(2): 139-42, 2000 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-10904139

RESUMEN

Testosterone metabolites (dihydrotestosterone, DHT) and 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol), but not testosterone itself, were shown to reduce the levels of very long chain fatty acids which accumulate in cultured skin fibroblasts from X-adrenoleukodystrophic patients (X-ALD). In addition, in X-ALD fibroblasts, testosterone is less actively converted into DHT vs. controls (skin fibroblasts retrieved from normal subjects) whereas the additional conversion of DHT to the final product 3 alpha-diol is enhanced. This is the first report of altered testosterone metabolism in X-ALD fibroblasts and of the effects of androgens in lowering the abnormal accumulation of very long chain fatty acids in this type of cells.


Asunto(s)
Adrenoleucodistrofia/metabolismo , Ácidos Grasos/metabolismo , Fibroblastos/metabolismo , Testosterona/metabolismo , Adrenoleucodistrofia/patología , Niño , Dihidrotestosterona/metabolismo , Humanos , Piel/citología , Piel/metabolismo , Piel/patología
17.
Neurosci Lett ; 250(3): 145-8, 1998 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-9708853

RESUMEN

The beta-oxidation of [3H] arachidonic acid (AA; 20:4 n-6) and the conversion of [1-14C]eicosapentaenoic acid (EPA, 20:5 n-3) to docosahexaenoic acid (DHA, 22:6 n-3) have been studied in skin fibroblasts from patients with inherited peroxisomal diseases, such as Zellweger (ZW) and X-linked adrenoleukodystrophy (X-ALD), from patients with Alzheimer's disease (AD), a non-inherited neuropathology, and from controls. EPA is not converted to DHA, while there is enhanced formation of the intermediate product 22:5 n-3 in ZW, when compared to X-ALD, AD and controls. We also confirmed that AA is not beta-oxidized to 4,7,10-hexadecatrienoic acid (16:3), a metabolite produced by peroxisomes, while being more effectively converted to the elongation product 22:4, in ZW, in comparison to X-ALD, AD and controls. The data demonstrate a defect in DHA synthesis and in AA beta-oxidation, and the occurrence of associated adaptative modifications in the metabolism of these long chain PUFA, in three Italian ZW patients.


Asunto(s)
Adrenoleucodistrofia/metabolismo , Enfermedad de Alzheimer/metabolismo , Ácido Araquidónico/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Fibroblastos/metabolismo , Piel/metabolismo , Síndrome de Zellweger/metabolismo , Humanos , Oxidación-Reducción , Piel/citología
18.
Thromb Res ; 78(2): 151-60, 1995 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-7482432

RESUMEN

This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC50s (concentration resulting in 50% inhibition) of DHPE for ADP or collagen-induced PRP aggregations were 23 and 67 microM, respectively. At 400 microM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects of PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavnoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.


Asunto(s)
Antioxidantes/farmacología , Eicosanoides/biosíntesis , Alcohol Feniletílico/análogos & derivados , Aceites de Plantas/química , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico , Adenosina Difosfato/farmacología , Antioxidantes/aislamiento & purificación , Colágeno/farmacología , Flavonoides/aislamiento & purificación , Flavonoides/farmacología , Humanos , Ácidos Hidroxieicosatetraenoicos/biosíntesis , Ácidos Hidroxieicosatetraenoicos/sangre , Glucósidos Iridoides , Iridoides , Aceite de Oliva , Alcohol Feniletílico/aislamiento & purificación , Alcohol Feniletílico/farmacología , Extractos Vegetales/química , Inhibidores de Agregación Plaquetaria/aislamiento & purificación , Piranos/aislamiento & purificación , Piranos/farmacología , Tromboxano B2/biosíntesis , Tromboxano B2/sangre
19.
Thromb Res ; 87(3): 315-22, 1997 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9263398

RESUMEN

We have evaluated the effects of hydroxytyrosol (HT), a potent antioxidant present in olive oil, on the formation of arachidonic acid 5-lipoxygenase metabolites by leukocytes in vitro. HT, a simple phenolic compound, extracted from first-pressure oil, was isolated by HPLC and characterized by gas chromatography/mass spectrometry. HT inhibited in a dose-related manner the production of leukotriene B4 (LTB4) by calcium ionophore-stimulated leukocytes. As expected, similar inhibition was observed for omega-oxidized metabolites of LTB4, namely 20-hydroxy and 20-carboxy-LTB4. The results disclose a new biological activity of olive oil-derived phenols on leukocyte eicosanoid production.


Asunto(s)
Antioxidantes/farmacología , Leucocitos/efectos de los fármacos , Leucotrieno B4/biosíntesis , Alcohol Feniletílico/análogos & derivados , Aceites de Plantas/química , Araquidonato 5-Lipooxigenasa/metabolismo , Calcio/fisiología , Cromatografía Líquida de Alta Presión , Depresión Química , Cromatografía de Gases y Espectrometría de Masas , Humanos , Ionóforos/farmacología , Leucocitos/metabolismo , Aceite de Oliva , Alcohol Feniletílico/aislamiento & purificación , Alcohol Feniletílico/farmacología
20.
Life Sci ; 73(12): 1567-75, 2003 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-12865096

RESUMEN

X-Adrenoleukodystrophy (X-ALD) is a peroxisomal disorder associated with the abnormal accumulation of very long chain fatty acids (VLCFA) in plasma and tissues. We have demonstrated that the androgen dihydrotestosterone (DHT) and 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol) have favorable effect on VLCFA metabolism. We have investigated the effect of androgens on peroxisomal beta-oxidation, the incorporation of labelled lignoceric acid into cholesterol esters and VLCFA elongation, in cultured skin-fibroblasts from control and X-ALD patients. The androgens significantly increased peroxisomal beta-oxidation in X-ALD fibroblasts although VLCFA levels were not normalized. The major effect was on the incorporation of labelled lignoceric acid into cholesterol esters, since the enhanced lignoceric acid incorporation into cholesterol ester fraction, which occurred in X-ALD fibroblasts, was reduced towards normal values. In contrast, the androgens had no effect on the elongation pathway.


Asunto(s)
Adrenoleucodistrofia/metabolismo , Androstano-3,17-diol/farmacología , Ésteres del Colesterol/metabolismo , Dihidrotestosterona/farmacología , Ácidos Grasos/metabolismo , Piel/efectos de los fármacos , Adrenoleucodistrofia/patología , Células Cultivadas , Niño , Fibroblastos/metabolismo , Humanos , Metabolismo de los Lípidos , Oxidación-Reducción , Peroxisomas/metabolismo , Piel/citología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA